Bariatric surgery is effective in treating extreme obesity in adults, and is most commonly used in the 5th decade of life. However, as the prevalence of extreme obesity in adolescence increases, more and more youth are seeking bariatric surgery. Many questions regarding the health benefits and risks of surgical weight loss in adolescents still remain. In 2006, Teen-Longitudinal Assessment of Bariatric Surgery (Teen-LABS) was awarded funds as an ancillary study to Longitudinal Assessment of Bariatric Surgery (LABS). The TeenLABS central hypothesis was that severe obesity in adolescence is associated with medical and psychosocial impairments which may be more effectively treated with bariatric surgery during adolescence rather than later in adulthood. During the initial 5 years of Teen-LABS, several noteworthy achievements were accomplished: establishment of a research infrastructure, including several sub-committees and work groups; enrollment of 207 subjects (through January 2011) - over 80% of the desired 250 subjects; infrastructure supporting 10 ancillary studies and 3 sub-studies; and collection and storage of biospecimens (DNA, serum, plasma, urine) in the NIDDK-Biospecimen Repository. The Data Coordinating Center (DCC) thus far has established a research infrastructure and database characterized by standardized and rigorous data collection, data accuracy, and completeness. The overarching goals ofthe Teen LABS study forthe five year renewal period will focus on the completion of stated goals ofthe Teen LABS protocol, in addition to several other new areas of scientific investigation. With this extension, the core functions of DCC will be to continue support of Consortium processes and investigators by focusing on core responsibilities including: data collection and management, statistical analysis and reporting, laboratory and repository sample tracking, partnership in study publications, coordination of study meetings, study staff training & certification. IRB and NIH reporting requirements, site auditing and monitoring, database quality assurance, coordination and support of all study committee functions, DSMB and Steering Committee meeting coordination, and informed consent tracking.